Patent GB-624467-A (GB)
Title: Improvements in or relating to record card controlled calculating machines
IPC: G06F7/44
Filed: 1946-12-18
Abstract: 624,467. Statistical apparatus. BRITISH TABULATING MACHINE CO., Ltd. Dec. 18, 1946, No. 37310. Convention date, Dec. 21, 1945. [Class 106 (i)] A cyclically-operated multiplying machine comprises means for sensing a record card for designations representing two factors to be multiplied together, multiplying and adding mechanisms, and recording means, and is characterized by the sensing means sensing in each cycle like denominational designations in the two factors in ascending succession of denominations and by the multiplying mechanism in each cycle effecting the cross multiplication of pairs of sensed digits to give partial products of like denominations and by the adding mechanism adding together the partial products, together with any carry resulting from the addition in the previous cycle, and by the recording means operating to record in each cycle the lowest digit of the last addition sum made. Consider, as an example, 245 x 379. First, the units digits 5 and 9 are sensed and multiplied together, the units digit (5) of the product being recorded, and the tens digit (4) being held for adding in during the following cycle. Next, the digits 7Î5 and 4Î9 are multiplied together, the sum of these partial products and the digit (4) carried from the previous cycle giving the tens digits (5) of the product for recording and a carry forward of 7, and so on. Card feeding mechanism. This is of the type shown in Specification 418,067, which is referred to. A picker 12, Fig. 3a, feeding the cards one by one from the bottom of a stack 10, is integral with a rack 14 in mesh with a gear 32 adapted to be driven by a motor M through worm gearing 16 and a clutch 18 controlled by a magnet 19. A spring drum 34 (not shown), geared to the wheel 32, returns the rack to its R.H. position upon disengagement of the clutch 18. At the extreme L.H. position of the picker mechanism, the leading edge of the card 10 is positioned between the jaws 54, 55, Figs. 3 and 9 of a carriage 50, which latter, at this time, is in its extreme R.H. position. The carriage 50 is secured to a second rack 43, Figs. 9 and 3a, which is driven through a one-way clutch 38 from the rack 14. When the carriage 50, Fig. 9, is in its extreme R.H. card-receiving position a projection 59 on a spring finger 58 is cammed upwards by an inclined member 60 and provides a locating stop against which the card is urged by constantly rotating worm-driven feeding rollers 61, Fig. 3. Energization of a magnet 71 rocks an arm 68, the lower end of which releases a latch 67 on the carriage from a spring- urged slide 66 which moves to the right, and, through a toggle linkage, closes the jaws 54, 55, and clamps the card to the carriage for subsequent step-by-step feeding under control of the usual magnet-operated double pawl and ratchet escapement. When the carriage 50 reaches its extreme L.H. position, another energization of magnet 71 causes the arm 68 to rock a bellcrank 77, which returns the slide 66 to its initial position,.thus breaking the toggle and releasing the grip on the card to allow the latter to be fed forward by the rollers 61 into the hopper 79. The carriage rack 43, Fig. 9, has secured thereto a pair of arms 126 and 127, travelling with the carriage, between which is held a programme card 128, Fig. 12, which controls the sequence of operations. Card reading devices. The constantly-rotating rollers 61, Fig. 3, are journalled in holders 105 located in a frame with side plates 106 toothed along upper and lower edges to provide for setting the holders in desired positions. All except the two extreme holders are provided with a set of six brushes 107, each of which contacts a separate insulated section of the related roller 61. A lower frame with similar toothed side plates 82 for locating brush holders 81, is supported on eccentric pins operable by a control knob (not shown) for withdrawing the lower brushes 62 from the rollers 61, after which the lower frame may be hinged downward to gain access to a card, etc. In the case of the programme card, a row of twenty-four reading brushes (not shown) co-operate with a roller comprising six insulated sections for sensing the control perforations. Punching mechanism. This is of known construction. It comprises magnets 111, Fig. 3a, operable to depress, through levers 112, corresponding keys 113 which are linked by bell-cranks 114 to interposers 110. The forward movement of an interposer 110 rocks a bail 116 which lifts a hook 117 closing contacts 118 to energize a magnet 119. Through linkage 120 the armature of magnet 119 pulls down a bail 115 pressing down the end of the advanced interposer 110 and actuating the corresponding punch 35. This action rocks a bail 121 which operates the carriage escapement; the latter can also be actuated without punching by energizing the magnet 119 directly, the bail 121 then being rocked by a special interposer not associated with a punch. When the record card 10, Fig. 12, is clamped in the carriage of the machine, its edges are aligned with those of the programme card 128 as shown. Two sets of reading brushes 62 sense the lowest digits of the multiplier 10A and multiplicand 10B, while the brushes 130 (not shown) sense the first column of control perforations in the programme card. Later, a selected punch is actuated to produce a representation of the lowest digit of the product 10C. The carriage is stepped on and repeats this process for each card column until the multiplication is complete; then a checking process follows under the control of field 128B of the card 128. The punchings 284 may be produced during the checking operation, if desired. Circuits. During each machine cycle a multiplier and multiplicand digit is sensed in the record card, and, through circuits which pass through perforations in the programme card, these digits are set up in holding relays arranged in a code system 1, 2, 4, 6, 8. There are six sets of relays for the multiplier and six sets for the multiplicand, and the selection of each set is controlled by relay-operated systems of contacts controlled by perforations in the programme card. The sets are selected successively as each digit is sensed and the energized relays are held as long as the corresponding digit is needed for the computation of the partial products. Fig. 18b (part) shows, diagrammatically, some of the stages during the multiplication 95,205 Î 256,339,801,479. The numbers 1 to 6 represent the sets of relays available for multiplicand (E) and multiplier (H) digits, and it will be noted how these are used in succession until, in the case of the multiplicand, all six have been used, and the earlier ones are then cleared for taking the higher digits. Cross multiplication takes place at each stage to obtain all partial products of the same order, which, together with the carry from the next lower order, are totalled, the " units " digit of the total (ringed in the Figure) being punched in the appropriate denominational position on the card. The cross multiplications represented on Fig. 18b are accomplished by systems of relaycontrolled contacts arranged between the multiplier and multiplicand holding relays, and cause the energization of (M) relays representing the partial products in a binary progression 1, 2, 4, 8, 16, 32 and 64. These partial product relays control contacts in an adding network (Figs. 15P to 15W, not shown) comprising binary progression stages 1 to 64 so arranged that wires representing 0, 2, 4, 6, 8 leaving each stage are connected to wires entering the next stage representing the units digit of twice their respective values. The M relays representing the partial products control contacts which have the effect, when transferred, of connecting the current-carrying wire to a wire of two units higher value; thus, in view of the doubling which takes place between each stage, the ultimate effect of each energized M relay depends on the number of stages between it and the terminal relays. Similar networks are provided for taking the tens and hundreds carries from the units network and the results from these are held on relays and added into the lower order networks during succeeding cycles. The energized terminal relay of the primary network initiates operation of a corresponding punch. Checking. After completion of the multiplying operation and recording of the product by punching in field 10C of the card 10, Fig. 12, the card passes under a second pair of brushes 62 for a second reading of the multiplier and multiplicand digits, and brush No. 2 is now used for reading the product perforations. A new process of multiplication now commences, different E and H relays being selected for holding the multiplier and multiplicand digits under the control of a different pattern of perforations in the " check " section of the programme card 128. Also, at each stage of multiplication, the nines complement of the appropriate product digit is added in (the usual correction being provided for the units digit), and since this is equivalent to subtraction of the product digit, the final digit at each stage should be zero. If this is not so the machine is stopped automatically and a signal lamp is illuminated. Provision is made for rounding off the lowest digit of the product to the nearest whole number in the higher denomination. Also, the result may be recorded in the binary code if desired. In a modified operation of the machine, six values of hours and minutes are sensed from the record card, one denomination in each cycle, and added together. The six digits are entered in the six sets of E relays and six " ones " are entered in the six sets of H relays. Thus, in effect, addition is accomplished by multiplying by one and adding the partial products. Special relays are included in the adding network to provide for the non-uniform radices. The machine can also be used for entering two pairs of factors